News Archives

Factors affect the sealing performance of butterfly valves

October 19, 2021

For the choice of butterfly valve, sealing is the most important attribute, because it directly affects the effect of butterfly valve throttling and is a direct manifestation of the quality of butterfly valve products. However, for most

wafer type butterfly valve, NBR seat (11)

working conditions, sealing does not mean that one drop is not allowed to leak. For the sealing performance of the butterfly valve, the accurate judgment standard should be: any sealing is allowed to have a small amount of leakage sometimes, if the leakage is not effective, it can be considered as sealed. The use experience of the valve shows that, in many cases, it is unnecessary to put high requirements on the sealing performance of the valve, because some working conditions completely allow a small amount of leakage of the medium, because this leakage is not enough to affect the use of the valve.
Of course, there are also more demanding working conditions in terms of sealing, usually for high pressure or corrosive media, and pipelines that transport flammable, explosive and toxic media. The leakage of the medium between the valve sealing surfaces may cause personal hazards, economic losses, and even In the event of an accident, etc., the tightness requirements should be reasonably put forward according to the danger level of the medium.
For example, for a hard-sealed butterfly valve, a certain amount of leakage is allowed when the sealing performance test is performed in the closed state in accordance with the technical standards for valve manufacturing. However, in order to ensure the high sealing performance of the hard-sealed butterfly valve, Tanghai Valve still carefully grinds the sealing surface, increasing the specific pressure on the sealing surface within the allowable specific pressure range of the sealing surface material, and improving the rigidity of the structure at the same time. At the same time, Tanghai Valve has stricter requirements on design, manufacturing and processing, such as:
(1) The quality of the valve body and bonnet, especially during forging or casting, should avoid defects and uneven composition such as folding, slag inclusion, pores, organization evacuation, and hidden cracks.
(2) The processing quality of the connecting parts of the valve stem and the valve body is improved, especially the roughness of the valve stem and the stuffing box, the straightness of the valve stem, the verticality of the stuffing box hole of the bonnet, and the processing accuracy are increased.
(3) The structure selection of the valve stuffing box. Since the seal at the valve stem is a dynamic seal, the packing is easy to wear during the rotation or sliding process of the valve stem. It is necessary to select a special low-leakage packing seal and packing seal combination, and strictly control the packing and packing. The gap between the valve stem, the gap between the packing and the stuffing box.
In summary, in addition to meeting the process conditions and standard specifications, the sealing performance of the control butterfly valve should also be fully considered for various operating conditions. In the engineering design, the sealing level of the butterfly valve should be selected to meet the principles of safety, reasonableness and economy.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Flange butterfly valve is more suitable for large and medium diameter pipelines

October 18, 2021

Commonly used butterfly valves include wafer butterfly valves, flanged butterfly valves and welded butterfly valves. Wafer type butterfly valve uses double-head bolts to connect the valve between two pipe flanges. Flange type

Double flange butterfly valve (16)

butterfly valve has flanges on the valve, and bolts are used to connect the flanges at both ends of the valve to the pipe flanges. The welding butterfly valve, as its name implies, is to weld the butterfly valve directly to the pipeline. The groove of the butt welding butterfly valve corresponds to the groove on the pipeline, and the welding rod is used to weld it. This type of connection is generally used in the case of high pressure media. Because welding is not easy to disassemble, the quality of the butterfly valve is required to be very high, and the price is naturally relatively high. Therefore, when DN50-300, flanged butterfly valve can be used, which is a cost-effective choice.
The flanged butterfly valve has its own flanges on both sides of the valve. Usually the flange and the valve body are cast together, so that the applicability to the pipeline is relatively strong, and it has the advantages of convenient installation and firmness. It is mainly used as a cut-off valve. Can have the function of a regulating valve. At present, flanged butterfly valves are used more and more on large and medium diameter, low pressure pipelines.
The butterfly plate of the flange butterfly valve is installed on the diameter side of the pipeline. The structural principle is very suitable for making large-diameter valves and has good fluid control characteristics. When the flange butterfly valve is in the fully open position, the thickness of the butterfly plate is the only resistance when the medium flows through the valve body. The larger the diameter, the lower the pressure. Therefore, the pressure drop generated by the flange butterfly valve is very small, so the flange butterfly valve can Actively play a role in large-diameter pipelines.
Flange butterfly valves are not only widely used in general industries such as petroleum, gas, chemical, water treatment, etc., but also used in cooling water systems of thermal power stations. The future market development prospects are bright.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

What are the characteristics of threaded gate valve in application

October 15, 2021

Commonly used pipeline connection methods are mainly: threaded connection, welding and flange connection. The threaded connection we mentioned today is actually also called threaded connection, which is also a connection

threaded gate valve-inner screw-wedge-EPDM (1)

method of gate valve, which connects the gate valve with the pipeline through internal and external threads.
Therefore, we can see that the types of threaded gate valves are divided into external thread type and internal thread type according to the thread position. According to the flow direction of the medium, there are straight-through type, direct-flow type and angle type. When the pipeline of the working condition is small-caliber and low-pressure, the threaded gate valve is generally used instead of the welded gate valve, so that the same cut-off effect can be achieved while saving the budget, and the cost performance is relatively high.
Below, let’s take a look at the specific characteristics of the threaded gate valve in the application?
(1) The flow resistance is small. The internal medium channel of the threaded gate valve is straight, the medium flows in a straight line, and the flow resistance is small.
(2) The threaded gate valve is more labor-saving whether it is opened or closed, because the medium pressure is not large.
(3) Water hammer is not easy to occur because it takes a long time to close.
(4) The threaded connection mode saves cost and is easy to install.
(5) The length of the structure is small, the shape is simple, and the scope of application is wide.
(6) The valve has good rigidity, smooth passage, small flow resistance, reliable sealing, light and flexible operation.
The threaded gate valve can be used for fully open and fully closed functions, and cannot be adjusted or throttled. Suitable for medium oil, water, steam, etc. For more details about the threaded gate valve, please contact our professional team to understand, we will be waiting for your inquiry 24 hours.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Characteristics of the centerline wafer butterfly valve

October 14, 2021

The centerline wafer butterfly valve is one of the commonly used butterfly valves. It is named because of the structure of the stem axis, the center of the butterfly plate and the center of the body at the same position. The structure of the centerline butterfly valve is very simple, and the installation and maintenance are also very

Wafer type butterfly valve with worm gear

convenient. As a component that controls the on-off and flow rate of the pipeline system, the centerline clamp valve is widely used in pipeline systems in the fields of petroleum, chemical industry, hydropower station, municipal construction, water supply and drainage.
The sealing form of the centerline wafer butterfly valve is generally a soft seal, and the sealing material is rubber or polytetrafluoroethylene, so the centerline wafer butterfly valve is usually a soft sealing butterfly valve. Therefore, the advantages of this type of valve are that the seal can be replaced, the sealing performance is excellent and reliable, zero leakage can be achieved, and two-way sealing can be achieved. . However, due to the limitation of its own structural characteristics, the centerline wafer butterfly valve also has some shortcomings. Because the butterfly plate and valve seat of the valve are always in a state of squeezing and scratching, the resistance distance is large, and the wear on the butterfly plate and valve seat is very large, so In order to overcome the phenomenon of squeezing and scratching and ensure the sealing performance of the valve, the valve seat of the centerline butterfly valve adopts elastic materials such as rubber or polytetrafluoroethylene to ensure the sealing performance of the valve. However, materials such as banana and polytetrafluoroethylene are subject to temperature restrictions in use. Therefore, the disadvantage of the centerline butterfly valve is that it is not resistant to high temperatures.
The centerline wafer butterfly valve is not suitable for high temperature and high pressure working environment, has poor wear resistance and short service life. These shortcomings make the scope of application of the valve have certain limitations. In order to overcome this problem, there is now a triple eccentric metal hard seal butterfly valve, which is different from the centerline wafer butterfly valve. The stem axis of the triple eccentric butterfly valve deviates from the center of the butterfly plate and the center of the body at the same time, and the rotation axis of the valve seat and the axis of the valve body channel There is a certain angle. Compared with the centerline butterfly valve, the triple eccentric butterfly valve is more resistant to high temperature, and also has good sealing performance and longer service life.
The valve body and the valve seat are connected components, and the sealing surface layer of the valve seat is welded with temperature-resistant and corrosion-resistant alloy materials. The multi-layer soft laminated sealing ring is fixed on the valve plate. Compared with the traditional butterfly valve, this butterfly valve has high temperature resistance, light operation, no friction when opening and closing, and when closing, the torque of the transmission mechanism increases to compensate for the sealing, which improves the butterfly valve. The advantages of sealing performance and extended service life.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Comparison of pin butterfly valve and pinless butterfly valve

October 13, 2021

We often hear such statements as pinless butterfly valves and pinless butterfly valves in the purchase of butterfly valves. Because of technological reasons, pinless butterfly valves are usually more expensive than pinned butterfly valves. This makes many customers think whether pinless butterfly valves are more expensive than pinless butterfly valves. Is it better to have a pin butterfly valve? How does a pin butterfly valve compare with a pinless butterfly

Wafer butterfly valve-PN20-WCB-ANSI-150 (3)

valve? This article introduces Tanghai Valve for you.
From the appearance point of view of the pin butterfly valve and the pinless butterfly valve, the most essential difference is whether there is a tapered pin positioning on the valve plate. The connection method that uses a pin to penetrate the valve plate and the valve stem is a pin butterfly valve, and vice versa is a pinless butterfly valve. For pin butterfly valves and pinless butterfly valves, they have their own advantages and disadvantages. The specific situation is as follows:
Appearance comparison-the pinned butterfly valve has obvious pin head protrusions, which is not as smooth and beautiful as a pinless butterfly valve, but in fact it does not have a huge impact on the overall appearance.
Process comparison-the structural processing technology of the pin butterfly valve will be relatively simple, but if it needs to be repaired after long-term use, it will be more troublesome to disassemble the shaft and valve plate. Because the pin usually hit is that the pile pin is hard pressed up with a press, it is not easy to take out the valve stem. The pinless butterfly valve is relatively complicated in structure and technology because of the different ways of

wafer-type-butterfly-valve-with-handle-13

transmitting torque, but the later maintenance and disassembly are more convenient and convenient for repair.
Stability comparison——Because the pin butterfly valve is fixed with pins, the stability is definitely better than the pinless structure. The pinless structure affects the accuracy of the action due to the wear of the mating surface of the axle and the gate after long-term action. Therefore, the quality of pinless butterfly valves produced by manufacturers without mature processing technology and equipment is more worrying. This is also to remind customers and friends that if there is a demand for non-sold butterfly valves, you must choose a manufacturer with sound qualifications and mature production experience like Tanghai Valve. After all, Tanghai Valve has been in the valve manufacturing industry for 24 years, and it will be more professional in terms of quality, craftsmanship and management.
Sealing comparison-Finally, let’s take a look at the comparison of sealing effects. There is a saying that in actual use, the pin butterfly valve may see the medium from the pinned place to between the valve plate and the valve stem. The hidden danger brought by this is that the pin will be corroded and broken after a long time, causing the valve to fail to work, or the ejector rod leakage or the internal leakage of the pipeline. However, many manufacturers have begun to notice this problem. For example, Tanghai will choose to weld a layer of pins on the valve plate and shaft to prevent leakage from the pins.
In summary, compared with pin butterfly valves and pinless butterfly valves, objectively speaking, each design has its own characteristics and advantages, and one cannot simply say which one is better. As long as we choose the product that is most suitable for our cost budget and most suitable for our working conditions, it is a good product that suits us.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Wafer type dual plate check valve: metal seated vs resilient seated

October 12, 2021

Wafer dual plate check valve is used for pure pipelines and industrial, environmental protection, water treatment, high-rise building water supply and drainage pipelines, to prevent the reverse flow of the medium. The check valve adopts a clamp type, the butterfly plate is two semicircles, and it adopts a spring for forced reset. The sealing surface can be built-up welding wear-resistant material or rubber lining, with a wide range of use and reliable sealing.

The check valve opening and closing parts are opened or closed automatically by the flow and force of the medium to prevent the medium from flowing back. The valve is called the check valve. Check valves belong to the category of automatic valves, which are mainly used in pipelines where the medium flows in one direction, and only allow the medium to flow in one direction to prevent accidents.

According to the structure of the check valve, it can be divided into three types: lift check valve, swing check valve and butterfly check valve. Lift check valves can be divided into two types: vertical and horizontal. Swing check valves are divided into three types: single valve, double valve and multi valve. The butterfly check valve is a straight-through type. The above-mentioned check valves can be divided into three types in connection form: threaded connection, flange connection and welding. A check valve is a valve that can automatically prevent fluid from flowing back. The disc of the check valve is opened under the action of fluid pressure, and the fluid flows from the inlet side to the outlet side. When the pressure on the inlet side is lower than that on the outlet side, the valve flap is

H46-double flanged dual plate check valve-metal seated

automatically closed under the action of the fluid pressure difference, its own

lug type dual plate check valve metal seated (3)

gravity and other factors to prevent the fluid from flowing back.

klug type dual plate check valve metal seated (1)The dual plate check valve is divided into flange dual plate check valve, lug dual plate check valve and wafer dual

plate check valve.

Classification of wafer dual plate check valves: hard-seal wafer dual plate check valve and soft-seal wafer dual plate check valve; of which soft-seal wafer check valve is divided into full-lined soft-seal wafer check valve and Semi-lined/normal soft-seal wafer dual plate check valve.

Features of Wafer dual plate Check Valve:

Simple structure and light weight, especially suitable for low-pressure large-diameter pipelines;
The paired clamp connection mode, the production process is simple, and the disassembly and assembly are convenient;
The check valve adopts the clamp type, the butterfly plate is two semicircles, and the spring is forced to reset. The sealing surface can be built-up welding wear-resistant material or rubber lining, with a wide range of use and reliable sealing.

Model: H76X/H76H/H76W
Name: Wafer dual plate check valve
Please refer to the main technical parameters and spare parts materials:
https://www.tanghaivalve.com/wafer-type-double-disc-swing-check-valve-introduction/
Product name: Wafer double plate check valve (soft seal)
National Standard Number: H76X

dual plates check valve photos-normal sealing (1)

Size range: DN40-DN1200
Pressure rating: PN10/16/25/40/64/100
Valve features: double valve plate design, short running track of the valve plate, spring load makes the valve plate close more quickly, effectively preventing water hammer
When the valve plate is opened, it is close to 90 degrees, and the pressure loss is small
Zero leakage
Size range: 2″ to 48″
Pressure range: 10bar-50 bar
Suitable flange: National standard or EN1092 PN10/PN16/PN25/PN40 or ANSI 125/150/300
Structure length: EN558 series 16, API594

Body material: gray cast iron, ductile iron, carbon steel, stainless steel, aluminum bronze
Valve plate material: ductile iron nickel-plated, stainless steel 201, stainless steel 304,

dual plates check valve photos- full rubber

stainless steel 316, aluminum bronze
Valve seat material: nitrile NBR, EPDM, oil and acid and alkali resistant fluorine rubber VITON-A, steam resistant fluorine rubber VITON-B, hard seal
Uses: Suitable for installation at the outlet of high-lift pumps, or as a bottom valve in front of the pump, suitable for water, sea water, steam, oil, chemicals, chlorine, oxygen, and steam. Can be installed horizontally or vertically.
Application scope:
It is suitable for industrial, environmental protection, sewage treatment, high-rise building water supply and drainage pipelines, etc. It can also be used for environmental systems with corrosive media such as power plants and steel plants gypsum slurry.

Product name: Wafer double plate check valve (metal seated)
National standard number: H76H(W)-16C(16P, 16R, 16RL)
Size range: DN40-DN1200

H76-wafer type dual plate check valve metal seated

Pressure rating: PN10/16/25/40/64/100
Temperature range: -20℃ -350℃
Body material: WCB, A105, CF8, CF3, CF8M.CF3M and other materials and special steel
Valve plate material: WCB, A105.2CR13, 304.304L.316.316L and other materials and special steel
Valve shaft material: A105.2CR13, 304.304L.316.316L and other materials and special steel
Valve seat material: 2CR13, 304.304L.316.316L, STL and other materials and special steel
Application range: water, steam, oil, nitric acid, acetic acid, strong oxidizing medium and urea and other media
More video for wafer dual plate check valve, please see below:
https://www.youtube.com/watch?v=pGrkznOd-JA
https://youtu.be/etwT8RX-S3Q
https://www.youtube.com/watch?v=XqRRI7o-LFI

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Gate valve has a broad market in the field of sewage treatment

October 11, 2021

The market situation is often complementary to the country’s development policies. As the country implements energy conservation and emission reduction strategies and accelerates the cultivation and development of strategic emerging industries, the construction scale and service scope of my country’s sewage treatment industry have

Socket welding gate valve-DN150-PN16-square hat (1)

gradually expanded. For gate valve products that are indispensable in the field of sewage treatment, it has entered a period of rapid development. The market demand for Tanghai gate valve products is increasing day by day, and it has a broad market space in the sewage treatment market.
Through the data feedback of Tanghai Valve Business Department, we can see that in addition to gate valves, butterfly valves, ball valves and other products are also popular valve products by customers, which play an important role in sewage treatment and are in strong demand. At present, the rate of urbanization in my country is continuously increasing, and the amount of water supplied by water plants and the scale of sewage treatment in sewage treatment plants are gradually increasing. Therefore, sewage treatment requires a large number of environmentally friendly valve equipment.
Although gate valve products are in great demand, domestic gate valve manufacturers have mixed good and bad products. Some valve manufacturers have poor product quality, low technical level, narrow export categories, varieties and regions, and are not competitive in the international market. But for veteran manufacturers like Tanghai Valve, challenges and opportunities coexist. On the one hand, competition in the valve market has become more fierce. Common gate valves, ball valves, globe valves and other product markets have begun to fight fierce price wars. This is a huge challenge for Tang Hai. On the other hand, market competition encourages the old valve manufacturers represented by Tanghai Valve to accelerate the integration of their products with international standards, enhance the competitiveness of enterprises and regions, promote the quality improvement and transformation and upgrading of gate valves and other valves, and realize the sustainable development of the valve industry.
On the road in the future, Tanghai Valve will open up more sales channels and increase effective production capacity for the application of gate valve products in the field of sewage treatment, so as to obtain more orders. Through the correct analysis of manufacturing, marketing, expansion, financial and other costs, effective cost control is achieved, and the company adheres to the sound development path that guides the enterprise toward environmental protection.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Introduction to the Features of Lever Wafer Butterfly Valve

October 9, 2021

Lever or Handle wafer butterfly valve is a kind of butterfly valve, usually with soft seal, which consists of a sealing surface made of rubber or fluoroplastic as a sealing material and a valve plate and stem made of carbon steel or

wafer-type-butterfly-valve-with-handle-13

stainless steel. Due to the limitation of the sealing surface material, the handle wafer butterfly valve is only suitable for water, gas, oil and other fluid media with a temperature of ≤80～120℃. The application fields include chemical industry, petroleum, electric power, textile, papermaking, construction water supply and drainage, etc. It is used for on-off control of normal temperature and pressure pipeline media on pipelines that transport various corrosive and non-corrosive fluid media in the engineering system, and can also be used for flow adjustment.
Handle wafer butterfly valves are generally only suitable for small-diameter valves, that is, valves with a diameter less than or equal to DN200mm. Because the small-diameter torque is relatively small, the opening and closing of the valve can be directly controlled by hand. The caliber is greater than 200mm, and according to the specific size of the caliber, it needs to be equipped with a turbine head, a pneumatic device or an electric device.
Because the handle wafer butterfly valve is a soft sealing butterfly valve, when the valve is installed and used, the valve must be opened at an angle, which is generally between 5°-10°. Do not allow the sealing surface rubber to be squeezed for a long time. state.
The main features of the handle wafer butterfly valve are:
1. The design structure is simple and unique, small in size, light in weight, and easy to operate.
2. Small-caliber operating torque is small, labor-saving and dexterous, opening and closing quickly.
3. It can be installed at any position of the pipeline, which is very convenient for installation and maintenance.
4. Handle wafer butterfly valves are usually soft-sealed, with reliable sealing performance, and can achieve two-way sealing with zero leakage.
5. The sealing surface material is easy to replace, resistant to aging, weak corrosion, and has a long service life.
Founded in 1994, Tanghai Valve is a professional valve manufacturer integrating design, development, production, sales, installation and service, and a high-quality valve manufacturer. The leading products include: wafer butterfly valves, flanged butterfly valves, hard-sealed butterfly valves, gate valves, butterfly check valves and other water series control valve products and related supporting pipeline accessories. The product sales range covers all parts of the country, and it has developed steadily in developing countries and regions such as Asia, Africa, and Latin America, and has successfully opened markets in developed countries and regions such as Europe and the United States. Products are widely used in water supply and drainage, electric power, petrochemical, metallurgical and other industries.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Medium temperature for butterfly valves of different materials

September 30, 2021

In the large number of butterfly valve enquiries made by Tanghai Valve every day, “medium temperature” is a frequently mentioned term. Because the different types of media have a great influence on the selection of valve varieties. Whether the medium is an ordinary liquid, a highly corrosive special medium, or a cement-like turbid

Double flange butterfly valve (7)

medium, all correspond to different valve types. Whether the medium is high temperature or low temperature also determines which material of the butterfly valve is more suitable and durable. Now let’s take a look at the medium temperature of various butterfly valve materials.
The main material involved here is the body and bonnet material of the butterfly valve. The corresponding medium temperature is as follows:
Cast iron-the highest temperature of the applicable medium is 300℃;
Nodular cast iron-the highest temperature of the applicable medium is 350℃;
Stainless steel ——The highest temperature of applicable medium is 600℃;
Polytetrafluoroethylene——Maximum operating temperature of applicable medium: -180~150℃;
Rubber —— The highest operating temperature of the applicable medium: natural rubber 60℃; nitrile rubber and neoprene rubber 80℃; fluorine rubber 150℃. When the valve lining is made of rubber or plastic, its temperature resistance shall prevail.
Gray cast iron-the highest temperature of the applicable medium is 250℃;
High silicon cast iron-the highest temperature of the applicable medium is 120℃;
Carbon steel-the highest temperature of the applicable medium is 425℃ (if 16Mn, 30Mn forgings can reach 450℃);
Alloy steel-the highest temperature of the applicable medium is 550℃;
Copper alloy-the highest temperature of the applicable medium is 200℃;
Titanium-the highest temperature of the applicable medium is 300℃;
In addition, there are relatively special ceramic and glass butterfly valves, which have poor temperature resistance and are generally used below 90°C. The temperature resistance of the enamel valve is limited by the material of the sealing ring, and the maximum medium temperature exceeds 150℃.
Among the above various butterfly valve materials, cast iron butterfly valves, spheroidal ink butterfly valves, stainless steel butterfly valves, PTFE butterfly valves, and rubber butterfly valves are widely used and have better overall performance. They also occupy a large number of daily orders for Tanghai valves. The proportion of products is very popular in the market. Tanghai Valve produces butterfly valve products of various specifications and materials. With 24 years of industry experience, I believe you will definitely choose your favorite high-quality butterfly valve here.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

What are the connection methods of gate valves for hydropower stations

September 29, 2021

Gate valves used in hydropower stations are often in a relatively special working environment, which also puts forward high requirements on the quality of the gate valves. Among them, the connection method it uses is also an important process composition. What we are going to share today is about the connection method of gate valves for hydropower stations.

DIN-F5-BB-NRS-soft seated-wedge gate valve (10)

The most common connection method used in gate valves of hydropower stations is mainly flange connection. This connection method is usually two flange pieces plus a number of fastening bolts and nuts, and the pipes are connected by pressing the middle flange gasket. Why do you think that flange connection is the most suitable method for gate valves in hydropower stations? This is mainly because the flange connection can withstand high-strength tensile, compression, torsion and shear resistance. The flange connection is a detachable joint, which has the advantages of convenient disassembly, high connection strength, and good tightness.
According to the shape of the joint surface, the flange connection can be divided into: smooth type, used for gate valves with low pressure; concave-convex type; tongue and groove type: widely used in corrosive media, with better sealing effect; trapezoidal groove type: Use an oval metal ring as a washer, which is used for gate valves with a working pressure of ≥64 kg/cm², or high-temperature gate valves; lens type: the washer is in the shape of a lens and is made of metal. Used for high-pressure gate valves or high-temperature gate valves with working pressure ≥100 kg/cm²; O-ring type: This is a newer form of flange connection, which is developed with the appearance of various rubber O-rings As a result, it is more reliable than ordinary flat gaskets in terms of sealing effect. In addition to flange connection, there is also threaded connection or ferrule connection, which is a simple connection method that can reliably prevent leakage and so on.
After a brief introduction, do you have your own ideas for the selection of gate valves for hydropower stations? If you need a gate valve for a hydropower station, please first consider Tanghai Valve. The gate valve produced by Tanghai Valve is mainly used in normal temperature and pressure environment, professional and high-quality, and professional technicians will give reasonable suggestions according to your working conditions, so that you can easily choose the right one. Of valve products, you are welcome to contact us at any time.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Factors affect the sealing performance of butterfly valves

Flange butterfly valve is more suitable for large and medium diameter pipelines

What are the characteristics of threaded gate valve in application

Characteristics of the centerline wafer butterfly valve

Comparison of pin butterfly valve and pinless butterfly valve

Wafer type dual plate check valve: metal seated vs resilient seated

Gate valve has a broad market in the field of sewage treatment

Introduction to the Features of Lever Wafer Butterfly Valve

Medium temperature for butterfly valves of different materials

What are the connection methods of gate valves for hydropower stations

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